Abstract

Due to the universality and high percentage demand of chest X-rays and the importance of this examination in diagnostic radiology, there is a strong need for the assessment of its entrance surface air kerma. Entrance surface air kerma (ESAK) has been measured for a total of 60 patients undergoing posteroanterior chest x-ray from conventional diagnostic radiology in three diagnostic centers in Ogun State, Nigeria. ESAK was measured based on the x-ray equipment output obtained from a CONNY II dose rate meter. The entrance surface air kerma for the selected hospitals A, B and C are 0.20, 0.30 and 0.43 mGy, respectively with an average of 0.31 mGy. Variance analysis was performed to evaluate the significance of the difference between the entrance surface air kermas. The variation in entrance surface air kerma found among diagnostic centers in this survey showed that there is need to assess radiological techniques of x-ray examination and the personnel, among different diagnostic centers. In addition, when the ESAK average value is compared with other average values in some countries, it showed that the ESAK for Nigeria in chest PA examination is higher than other countries except Iran. This shows that optimal protection of patient against excessive radiation dose is possible by improving the influencing factors in diagnostic radiology examinations.

Key words: ESAK, posteroanterior, CONNY II, radiological techniques, optimal protection.